As a photopolymerizable composition, for example, there is a photopolymerizable composition, in which a photopolymerization initiator is added to a polymerizable compound having an ethylenic unsaturated bond. Such a photopolymerizable composition is polymerized and cured by being irradiated with light, and is used for a photocurable ink, a photosensitive printing plate, a color filter, various photoresists, and the like.
Further, there is another embodiment, in which, for example, a photopolymerizable composition generates an acid by being irradiated with light, and the generated acid is used as a catalyst. Specifically, the photopolymerizable composition is used for a material for image formation, forgery prevention, and energy radiation-dose detection, by utilizing the color reaction of a dye precursor catalyzed by the generated acid, or the photopolymerizable composition is used for a positive-working photoresist, and the like for manufacturing a semiconductor, a TFT, a color filter, a component for a micromachine, and the like, by utilizing a decomposition reaction by the generated acid.
In recent years, in particular, photopolymerizable compounds that are sensitive to a light source having a short wavelength (for example, 365 nm and 405 nm) have been demanded for various uses, and demand for compounds having excellent sensitivity to such a short wavelength light source, for example, for photopolymerization initiators, has been increasing. However, photopolymerization initiators having excellent sensitivity are generally unstable, and accordingly, photopolymerization initiators simultaneously achieving increased sensitivity and storage stability simultaneously, are desired.
For this reason, as photopolymerization initiators used for the photopolymerizable composition, oxime ester derivatives are proposed (for example, refer to U.S. Pat. No. 4,255,513, U.S. Pat. No. 4,590,145, Japanese Patent Application Laid-Open (JP-A) No. 2000-80068, JP-A No. 2001-233842, JP-A No. 2006-342166, and JP-A No. 2007-231000). However, since these known oxime ester compounds have low light absorptivity in the wavelength of 365 nm and/or the wavelength of 405 nm, they are still unsatisfactory in view of sensitivity.
Further, currently, photopolymerizable compositions which have excellent storage storability and excellent sensitivity to light in short wavelengths such as 356 nm and/or 405 nm or the like are also desired.
Furthermore, a colored radiation-sensitive composition for color filters, which contains an oxime compound, is disclosed (for example, JP-A No. 2005-202252); however, the storage stability and the sensitivity to lights of short wavelengths were still insufficient.
Moreover, in colored radiation-sensitive compositions for color filters, the reproducibility of color hue after pattern formation is a new issue, and a solution to the problem of change in colorability with the passage of time has been strongly desired.
Meanwhile, for the purpose of improving image quality owing to the light collectivity and the high color separation property of a solid-state imaging device such as a CCD in the color filter for image sensors, there is a strong demand for high color density and thinning of color filters. When a colorant is used in a large amount in order to obtain a high color density, the sensitivity for reproducing a minute pixel pattern shape of 2.5 μm or less with high fidelity becomes insufficient, and defects in the overall pattern tend to occur frequently. In addition, in order to eliminate these defects, light irradiation with high energy is required so that light exposure tine is prolonged, thereby reducing the production yield remarkably.
As described above, from the viewpoint of the necessity of obtaining good pattern formability while the colored radiation-sensitive composition contains a colorant (coloring agent) in the filter at high concentration, currently, it is required that the sensitivity of the colored radiation-sensitive composition for color filter be high.